

#import "PywCipherUtils.h"
#import "CommonCrypto/CommonDigest.h"
//#import "openssl_wrapper.h"
//#import "NSDataEx.h"


@implementation PywCipherUtils

+ (NSString *)md5:(NSString *)text
{
    const char *cStr = [text UTF8String];
    unsigned char result[CC_MD5_DIGEST_LENGTH];
    CC_MD5(cStr, strlen(cStr), result);
    return [[NSString stringWithFormat:@"%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X", result[0], result[1], result[2], result[3], result[4], result[5], result[6], result[7], result[8], result[9], result[10], result[11], result[12], result[13], result[14], result[15]] lowercaseString];
}

+ (NSData *)encryptRSA:(NSString *)publicKey plainData:(NSData *)plainData
{
    // 得到公钥文件
    //NSData *certificateData = [GTMBase64 decodeString:publicKey];
    NSData *certificateData = [PywCipherUtils base64Decode:publicKey];
    SecCertificateRef certificate = SecCertificateCreateWithData(kCFAllocatorDefault, (CFDataRef)certificateData);
    SecPolicyRef policy = SecPolicyCreateBasicX509();
    SecTrustRef trust;
    OSStatus status = SecTrustCreateWithCertificates(certificate, policy, &trust);
    SecTrustResultType trustResult;
    if (status == noErr) {
        status = SecTrustEvaluate(trust, &trustResult);
    }
    
    SecKeyRef pk = SecTrustCopyPublicKey(trust);
    CFRelease(certificate);
    CFRelease(policy);
    CFRelease(trust);
    
    // 分配内存块,用于存放加密后的数据段
    size_t cipherBufferSize = SecKeyGetBlockSize(pk);
    uint8_t *cipherBuffer = malloc(cipherBufferSize * sizeof(uint8_t));
    /* 苹果官方文档给出的说明是,加密时,如果sec padding使用的是kSecPaddingPKCS1,
     那么支持的最长加密长度为SecKeyGetBlockSize() - 11,这里说的最长加密长度,
     估计是包含了字符串最后的空字符'\0',因为在实际应用中我们是不考虑'\0'的,所以,
     支持的真正最长加密长度应为SecKeyGetBlockSize() - 12
     */
    double totalLength = [plainData length];
    size_t blockSize = cipherBufferSize - 11; // 使用cipherBufferSize - 11是错误的
    size_t blockCount = (size_t)ceil(totalLength / blockSize);
    NSMutableData *encryptedData = [NSMutableData data];
    // 分段加密
    for (int i = 0; i < blockCount; i++) {
        NSUInteger loc = i * blockSize;
        // 数据段的实际大小.最后一段可能比blockSize小.
        int dataSegmentRealSize = MIN(blockSize, [plainData length] - loc);
        // 截取需要加密的数据段
        NSData *dataSegment = [plainData subdataWithRange:NSMakeRange(loc, dataSegmentRealSize)];
        OSStatus status = SecKeyEncrypt(pk, kSecPaddingPKCS1, (const uint8_t *)[dataSegment bytes], dataSegmentRealSize, cipherBuffer, &cipherBufferSize);
        if (status == errSecSuccess) {
            NSData *encryptedDataSegment = [[NSData alloc] initWithBytes:(const void *)cipherBuffer length:cipherBufferSize];
            // 追加加密后的数据段
            [encryptedData appendData:encryptedDataSegment];
//            [encryptedDataSegment release];
        } else {
            if (cipherBuffer) {
                free(cipherBuffer);
            }
            return nil;
        }
    }
    
    if (cipherBuffer) {
        free(cipherBuffer);
    }
    
    CFRelease(pk);
    
    return encryptedData;
}

+ (NSData *)base64Decode:(NSString *)string
{
    unsigned long ixtext, lentext;
    unsigned char ch, inbuf[4], outbuf[4];
    short i, ixinbuf;
    Boolean flignore, flendtext = false;
    const unsigned char *tempcstring;
    NSMutableData *theData;
    
    if (string == nil) {
        return [NSData data];
    }
    
    ixtext = 0;
    
    tempcstring = (const unsigned char *)[string UTF8String];
    
    lentext = [string length];
    
    theData = [NSMutableData dataWithCapacity: lentext];
    
    ixinbuf = 0;
    
    while (true) {
        if (ixtext >= lentext){
            break;
        }
        
        ch = tempcstring [ixtext++];
        
        flignore = false;
        
        if ((ch >= 'A') && (ch <= 'Z')) {
            ch = ch - 'A';
        } else if ((ch >= 'a') && (ch <= 'z')) {
            ch = ch - 'a' + 26;
        } else if ((ch >= '0') && (ch <= '9')) {
            ch = ch - '0' + 52;
        } else if (ch == '+') {
            ch = 62;
        } else if (ch == '=') {
            flendtext = true;
        } else if (ch == '/') {
            ch = 63;
        } else {
            flignore = true;
        }
        
        if (!flignore) {
            
            short ctcharsinbuf = 3;
            
            Boolean flbreak = false;
            
            if (flendtext) {
                if (ixinbuf == 0) {
                    break;
                }
                
                if ((ixinbuf == 1) || (ixinbuf == 2)) {
                    
                    ctcharsinbuf = 1;
                    
                } else {
                    
                    ctcharsinbuf = 2;
                    
                }
                
                ixinbuf = 3;
                
                flbreak = true;
                
            }
            
            inbuf [ixinbuf++] = ch;
            
            if (ixinbuf == 4) {
                
                ixinbuf = 0;
                
                outbuf[0] = (inbuf[0] << 2) | ((inbuf[1] & 0x30) >> 4);
                
                outbuf[1] = ((inbuf[1] & 0x0F) << 4) | ((inbuf[2] & 0x3C) >> 2);
                
                outbuf[2] = ((inbuf[2] & 0x03) << 6) | (inbuf[3] & 0x3F);
                
                for (i = 0; i < ctcharsinbuf; i++) {
                    [theData appendBytes: &outbuf[i] length: 1];
                }
            }
            if (flbreak) {
                break;
            }
        }
    }
    
    return theData;
}

+ (NSString *)base64Encode:(NSData *)data
{
    static char base64EncodingTable[64] = {
        
        'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
        
        'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
        
        'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
        
        'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'
        
    };
    
    int length = [data length];
    
    unsigned long ixtext, lentext;
    
    long ctremaining;
    
    unsigned char input[3], output[4];
    
    short i, charsonline = 0, ctcopy;
    
    const unsigned char *raw;
    
    NSMutableString *result;
    
    
    
    lentext = [data length];
    
    if (lentext < 1)
        
        return @"";
    
    result = [NSMutableString stringWithCapacity: lentext];
    
    raw = [data bytes];
    
    ixtext = 0;
    
    
    
    while (true) {
        
        ctremaining = lentext - ixtext;
        
        if (ctremaining <= 0)
            
            break;
        
        for (i = 0; i < 3; i++) {
            unsigned long ix = ixtext + i;
            if (ix < lentext)
                input[i] = raw[ix];
            else
                input[i] = 0;
        }
        
        output[0] = (input[0] & 0xFC) >> 2;
        
        output[1] = ((input[0] & 0x03) << 4) | ((input[1] & 0xF0) >> 4);
        
        output[2] = ((input[1] & 0x0F) << 2) | ((input[2] & 0xC0) >> 6);
        
        output[3] = input[2] & 0x3F;
        
        ctcopy = 4;
        
        switch (ctremaining) {
            case 1:
                ctcopy = 2;
                break;
            case 2:
                ctcopy = 3;
                break;
        }
        
        for (i = 0; i < ctcopy; i++)
            [result appendString: [NSString stringWithFormat: @"%c", base64EncodingTable[output[i]]]];
        
        for (i = ctcopy; i < 4; i++)
            [result appendString: @"="];
        
        ixtext += 3;
        
        charsonline += 4;
       
        if ((length > 0) && (charsonline >= length))
            
            charsonline = 0;
        
    }     
    return result;
}

+ (NSString *)stringHiddenWithString:(NSString *)string count:(int)count replacement:(NSString *)replacement{
    
    if (string.length == 0|| count < 1) {
        return string;
    }
    
    long offset = 0;
    
    if (string.length - count > 0) {
        offset = (string.length - count) / 2;
    }
    
    NSMutableString *replace = [NSMutableString string];
    
    for (int i = 0; i < count; i ++) {
        [replace appendString:(replacement)];
        //[replace stringByAppendingString:replacement];
    }
    NSString *hide = replace;
    
    string = [string stringByReplacingCharactersInRange:NSMakeRange(offset, count) withString:hide];
    
    return string;
}


@end
